Floodlight



Dec. 15, 1931. L, x. CHAMPEAU FLOODLIGHT Filed June 5, 1929 2Sheets-Sheet l Dec. 15, 1931. L. X. CHAMPEAU FLOODLIGHT Filed June 5,1929 2 Sheets-Sheet 2 INVENTOR ATTOR EY! Patented Dec. 15, 1931 cnmmmorNEWYORK; N. Y.

r rLoonLIenr l Applicatioii iiledjailed}, 1929.l,erial 1i'q.367,8?8," i

This imentm relates fflood i he 'S'INK as are used for moving picture won o 7. other photographic purposes,-y although $1 invention is notlimited to this An object of the invention is to roduce a light of thischaracter which jshal be free from the objections existing in lights nowin use, which gives a very even illuminationover a flat field and whichmay be constructed a very reasonable cost.

A further object of the invention relates to the mounting of the lightwhereby it may; be

readily adjusted and whereby a pluralityof lights may be adjusted tomeet'different re-' quirements of illumination. 7

In flood lights with which I am familiar the reflecting surface extendsover the whole area of the reflector and it is not economically possibleto make these polished surfaces sufficiently optically accurate to giveeven' illumination to the object to be photographed. The result is aseries of rings in the photographs. On t e other hand, if reflectors ofthis sort are not highly polished,

but are merely light-diffusing surfaces, such a large percentage of thelight is lost that the efficiency as a whole is very much reduced.

My invention overcomes these disadvantages and provides at reasonablecost a light havin high efiiciency.

In the preferred form of my invention my flood light consists of a lightsource placed at the center of curvature of a relatively small sphericalmirror, which mirror, due to its small size, may be accurately ground atreasonable cost. Combined with this is a hood which may be made ofaluminum or other material and the inner surface of which is notsufliciently polished to constitute a re- 10 fleeting surface in theoptical sense, but which surface is finished so as to give what might betermed a diffused reflecting surface.

In order that the combination of mirror and hood may give asubstantially even illumination over a flat surface I prefer to form thehood in such a way that the light reflected from it covers the samefield as the light reflected from the mirror but tending to give greaterintensity at the outer edges, and since the light reflected from themirror and the li ht construction;

which show up light directly coming 'frornthe source of}illuminationtends'to throw a stronger light 7 at the center, thecombination givesfa nearly A uniform light on a flat field. a

V Otherffeaturesand advanta es willbecoine apparent from the followingescription and claims when considered in connectionfwith theaccompanying drawings in which' Figure 1 is a view partly in section andpartly in side elevation of my improved flood Fgure 2 isa frontelevation; 1

Figure 3 aview looking upward V "Figure 4a section on line 44 of Figure5; "Figure 5 a back view showin the mounting arrangement forseveral liits; "and" Figure 6 asideview of severa lights turned,at'diflerent-angles. 1

Referring to thedrawings, lj indicatesfa bracket having a ring portion 2shown in Figure 5jandin dotted lines in Figure H 3 is] a flaredho'odhavingformed inte al therewithajsocket''of Sphericnshape; he

hood also has a cylindrical portion fifitting the inn er surfaceof thering and also hasfl bent out lring portions 5a (with a re-Vflectorfiengages. ring 21 carries screws j 7 which engage f thereflector as indicated in Figure for holdingitin placei The brack et lalsfohasallowerarInB suitably shaped for supporting the hqedat its outeredge, as, forinst ance,bya screw-9, Figure 1. The] arm 8 is slotted forthe reception of a source of light," this consisting o'fjan electricblilb having a socket 1 1,the lower portion of which] isscrew-threadedat' 12 and athumb screw 13 engages the threads for adjustably securing the light injthe bracket. The bulb of the light isshown at '14 andthe filamentior source Theinnerisurface ofthe flaredhoodis not intended to be light-reflecting in the sense and itstwoparallel surfaces are accurately "1 ground and the backsurface issilvered; The

mirror iireflectforms.a 'portion of a s pheriji cal shell. h i i isubstantially atthe center of curvature of the" The isource oflight issituated a,

spherical surface of the mirror so that the result is a reflection alongthe radius of curvature of all light falling upon the mirror.

The flare of the hood is such that no reflected light from the mirrorfalls upon the inner surface of the'hood, this surface acting as adiffusing surface, and is so shaped that the light directly falling uponit from ,the source of light 15 tends to be thrown toward the outeredges of the field covered'by the light itself and the reflection fromthe mirror.

We thus have three overlapping sourcesof light, covering the same field,one direct from the light 15, the other two-indi-re'ct i.-, e.reflection from the mirror a-nd diffusedv reflection fromth'einnersurface. of the hood.: hen projected on, a "flat field thecenter; of the fleld'is somewhat more intensively illuminatedthan aretheedges, in so, faraslight comingfrom the, light source and from themirror are concerned. On; the other hand, by formingtheinnersurface ofthe hood sothat the diffused reflection, from said surface tends to, be.greaterat the edges of the field than at the center thereof, thewholefield is more evenly illuminated than ispossible with reflectorsnow available.

The, mirror itself is relatively small compared, with theentirestructure and therefore can be ground optically perfect and produce, thesame optical effect asif theientire surface of thehood, including thatportion occupied by the. mirror, were likewise optically'per- 5. fectlyground.

In the ,use of flood lights it'frequently happens'that the object tobeillumined -requires different illumination for different parts and anumber. of lights arev frequently qliemployed, It is very desirablethatthese lights ,maybejconveniently adjusted to give differentdegreesof illumination :to different portions of thearea illuminated. Todo this in a ,convenient and veconomical manner, I haveprovided a veryefficient form of bracket whichicanbeduplicated to any extent and anynumber ofjli'ghts may beus'ed together and.- adiustedto suitvaryingconditions.

To this end, the bracketlis formedzwith Q..an ,upperpivota1 portion 16projecting from the ring Projecting; in the opposite direction is aportion 17 which carries a bearing; for a pivot at'right angles tothepivot 16. Each bracket isfmadeexactly alike and for- 5& ,th'e purposeof connecting one bracket to an; other, Lprovide arigid member 18, oneend ofQWhiclifhas a ,pivotal bearing matching the pivotal bearing in thearm 17 and the other endof which has a hearing which fits the .pivot16., Adjusting screws 20 provide means for holding the parts of thebracket inthe desired position. In Figure 6-1 ,haveshown four. lightsdifferently positioned to illustratethenway inwhich the brackets may becaused to direct the light ,asdesired,

Having thus described my invention, what I desire to secure by UnitedStates Letters Patent and claim is:

1. A flood light comprising a bracket of ring shape, a flared hoodhaving a socket fitting the interior of the ring, a spherical mirrorsituated in the socket, and means carriled'by theringg-for holdinggtheumirror in p ace.

2. A flood light comprising a hood having niinllfllisligbt-i ifinsingsurface, a socket integral with the hood, said socket having a sphericalportion and a circular portion, a bracket of ring shape engaging thecircular portion of the socket, and a mirror seated in the socket: andsecured ,in place by. means carried'by the ring, 'v

3. A flo'od'light comprising a, bracketincluding a ring shapedportion,,,an arm..ex.-. tending fr'omthe ring forming arpivot, a

second arm extending from the ,ring andi forming a b'earmgfor apivot atright angles,

to the first-mentioned'pivot,anda rigid member havingone endjformedjwith a bearing matching the bearing on said second arm and itsother end having a bearingfittingthe pivot on the first arm,

Signed at New York-, New York, this27th LAWRENCE, X. CHAMPEAU.

